The present invention relates to an electro-magnetic clutch control system for automobiles, and more particularly to a clutch control system for changing the characteristic of the clutch with respect to car speed to prevent car knock.
In an electro-magnetic clutch, the clutch current flows through a coil to provide an electro-magnetic field, so that two members in the transmitting system are connected magnetically with each other to transmit the power from the engine to the transmission. An electro-magnetic powder clutch is a type of the above-mentioned electro-magnetic clutch.
An electro-magnetic powder clutch comprises an annular drive member secured to the crankshaft of an engine, a driven member installed on an input shaft of the transmission spaced from and leaving a small gap relative to the drive member, a magnetizing coil provided in the one of the members, and a shift lever for shifting (i.e. changing) the gears in the transmission. The shift lever is provided with a switch for the magnetizing coil, which is actuated by operating the shift lever. When the shift lever is shifted to the gear engaging position, the switch is closed making the electric current flow through the magnetizing coil to magnetize the member having the magnetizing coil. As the accelerator pedal is depressed, the current applied to the coil increases. The magnetic powder is aggregated in the gap between the drive member and the driven member, bringing about a connection between the drive member and the driven member. The clutch current passing through the magnetizing coil progressively increases according to how far the accelerator pedal is depressed, while the clutch slips between the drive member and the driven member. Thus, the vehicle may be smoothly and easily started by depressing the accelerator pedal without operating a clutch pedal. This is a well-known technique.